Mechanism for the control of reversible step-by-step rotation of selector drums of circular knitting machines

ABSTRACT

Each selector drum of a circular knitting machine is associated with a control device including two coaxial pairs of axially spaced apart like toothed wheels, the wheels of each pair being fixed together with the teeth of one wheel angularly dephased by half a pitch in relation to those of the other. A cam able to selectively occupy four discrete positions is mounted on a rotatable crown so that each revolution it may angularly displace a selected wheel by half a pitch or a pitch depending on the initial position thereof, this displacement being transmitted into a rotation of the drum by one or two steps of its selection members in a selected direction according to the pair of wheels acted upon.

United States Patent 119 Bourgeois Jan. 8, 1974 6 MECHANISM FOR THE CONTROL OF 3,093,987 6 1963 Zahradka 6t 61' 66/50 B REVERSIBLE STEP BY STEP ROTATION 3,004,413 10/1961 Felker 66/50 B OF SELECTOR DRUMS OF CIRCULAR FOREIGN PATENTS OR APPLICATIONS KNITTING MACHINE 451,679 8/1936 Great Britain 66/50 R Inventor: Norbert Paul Bourgeois, y 1,335,710 7/1963 France 66/50 B France Primary Examiner lames Kee Chi [73] Assignee: Etudes et Bonneterie S.A. R wenderoth et [22] Filed: June 1, 1972 [57] TRACT [21] Appl' 258783 Each selector drum of a circular knitting machine is associated with a control device including two coaxial [30] Foreign Application Priority Data pairs of axially spaced apart like toothed wheels, the June 7, 1971 Switzerland 8250/71 Wheels Of each P being fixed together with the teeth of one wheel angularly dephased by half a pitch in re- 52 US. Cl 66/50 B lation to those of the Other- A cam able to Selectively [51 Int. Cl. D04b 15/74 py four discrete positions is mounted on a rotat- [58] Field Of Search 66/50 B, 50 R, 50 A, able crown so that each revolution it y angularly 66/154, 156, 25, 36 R, 36 A, 504 displace a selected wheel by half a pitch or a pitch depending on the initial position thereof, this displace- 5 R fer n e Cited ment being transmitted into a rotation of the drum by UNITED STATES PATENTS one or two steps of its selection members in a selected 3,587,253 6/1971 G116 66/50 B accordmg to the of wheels acted upon 2,382,757 8/1945 Wawzonek 66/50 B 9 Claims, 8 Drawing Figures PMEMEB JAN 81974 SHEU 3 [IF 5 MECHANISM FOR THE CONTROL OF REVERSIBLE STEP-BY-STEP ROTATION OF SELECTOR DRUMS OF CIRCULAR KNITTING MACHINES BACKGROUND OF THE INVENTION The invention relates to control of the step-by-step reversible rotation of selector drums of circular knitting machines.

' On such machines, it is known to use patterning devices comprising selector drums which control placing of the needles or other knitting components into or out of operation. These drums generally carry a plurality of equidistant longitudinal selection members each including protruding elements the number and arrangement of which are established according to a predetermined selection scheme.

During operation of the machine, the drums are made to turn step-by-step by the action of a control mechanism, their selection members temporarily stopping facing a bank of intermediary selection levers disposed in stepped formation and which, by cooperating with the protruding elements, select the needles or other knitting components.

To conciliate the advantages offered by selector drums with a large selection capacity, i.e. comprising a large number of selection members, and which enable the obtention, by a unidirectional step-by-step rotation, of large area knitted designs, with the production of a design of reduced area or several small designs knitted according to an arbitary disposition, it is necessary to be able to impart at will to the selector drums a reversible intermittent rotation, either step-by-step of the selection members or a plurality of complete steps at a time.

Various control mechanisms have already been proposed. In certain of these, a toothed wheel is associated with each drum, either directly or through pinions, and control devices, each having at least two mobile elements, are provided to act on the teeth of the wheel on either side of its axis.

In other types, two superimposed toothed wheels, each adapted to control rotation of the drum in one direction, are also associated directly or indirectly with the drum and are. actuated by one or the other of two control devices provided with mobile elements able to selectively impart a rotation corresponding to one or several teeth.

These various types of mechanism require the employment of two separate automatically actuated control devices and must each comprise several mobile elements the position of which is selectively controlled. Apart from their relative complexity, such mechanisms require particular care to be taken at the moment of programming their operation; any unwanted simultaneous control of the two devices, which are each adapted to control rotation of the drum in only one direction, would inevitably cause a seizing up of the mechanism and risk causing the rupture of certain parts. This danger can only be avoided by the adjunction of auxiliary safety mechanisms neutralizing the effect of one device during operation of the other.

SUMMARY OF THE INVENTION An aim of the invention is to provide a control mechanism which remedies these drawbacks.

According to the invention, a mechanism for the control of reversible step-by-step rotation of selector drums of patterning devices for the control of knitting components of circular knitting machines, which drums each have on their periphery a series of equidistant selection members, comprises a control device associated with each drum including two pairs of axially spaced apart toothed wheels, said pairs of wheels respectively controlling rotation of the drum in one direction and in the other direction, the toothed wheels of each pair having the same number of teeth and being fixed together coaxially with the teeth of one wheel angularly dephased by half a pitch in relation to the teeth of the other, and a control member comprising an active part able to selectively occupy four discrete positions corresponding to the four axial positions of the toothed wheels, said control member being relatively movable past the toothed wheels such that said active part contacts a selected wheel to rotatably displace the corresponding pair of wheels either by half a pitch or by a full pitch of the teeth thereof which causes an angular displacement of the drum by one or two steps of its selection members in a selected direction.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the mechanism according to the invention are shown, by way of example, in the accompanying drawings, in which:

FIG. 1 is a schematic cross section of a part of a circular knitting machine, showing the selector drum of a patterning device and its control mechanism;

FIGS. 2 and 3 are partial plan views respectively taken along section lines A-A and B-B' of FIG. 1;

FIG. 4 is a schematic view of a detail during operation;

FIG. 5 is a schematic cross section of a second embodiment;

FIG. 6 is a plan view taken along section line C-C' of FIG. 5;

FIG. 7 is a cross sectional view showing parts of the control mechanism common to the set of patterning devices of the two embodiments of knitting machine; and

FIG. 8 is an elevational view of a detail of FIG. 7.

DETAILED DESCRIPTION OF THE INVENTION ,A selector drum 1 of the knitting machine of FIGS. 1 to 3 has on its periphery a series of longitudinal selection members formed by equidistant radial grooves in which are inserted selection blades 2 carrying fragmentable butts 3 adapted to control the selection of needle jacks, not shown, through a bank of schematically shown stepped selection levers 4.

The drum 1 is fixed to a shaft 5 freely rotatably mounted in a bearing of a stationary plate 6 of the machine. At the lower end of the shaft 5 are keyed two driving elements, namely a pinion 7 and a chainwheel 8.

Rotational drive of the drum 1 can take place in the two directions, either step by step of the selection members, or by two steps at a time, by means of the mechanism described below.

On a shaft 9, carried parallel to the shaft 5 by the stationary plate 6, are turnably mounted a control pinion l0 meshing with the pinion 7 and a chainwheel ll drivably connected to the chainwheel 8 by means of a chain 12. This latter arrangement enables driving of the selector drum in the two directions from a unidirectional drivingrotation of one or the other of pinion and chainwheel 11; it also enables avoidance of the use of a reversing pinion the lateral disposition of which would substantially increase the width of the mechanism, which would lead to a reduction of the number of selector drums of the knitting machine.

Two pairs of coaxial toothed wheels 13, 14 and 15, 16 are respectively fixed to the pinion 10 and to the chainwheel 11, in a manner to form two distinct rotary assemblies separated by a spacing ring 17; the three components of each assembly may be made in a single piece, for example by moulding.

These four toothed wheels all have the same diameter and the same number of teeth and, for each pair, the teeth of one wheel are angularly staggered in relation to the teeth of the other wheel by half the pitch between adjacent teeth (FIG. 2 and 3). Moreover, the respective ratios between the number of teeth of pinions 7 and l0and between those of the chainwheels 8 and 11 are such that for each toothed wheel a one pitch displacement, Le, a rotation corresponding to the angular separation between two consecutive teeth, causes a rotation of the drum 1 by two steps of the selection blades 2.

Control of the toothed wheels is carried out by passage of a cam 18 slidably mounted, along a direction parallel to the shaft 9, on a support 19 fixed to a rotary crown 20 supporting the needle bearing cylinder (not shown). This cam can be submitted, upon passage, to

the action of a control mechanism such as that shown in FIGS. 7 and 8, this mechanism being controlled by a program in a manner such that an active part 21 of the cam 18 may occupy a selected one of five discrete positions; four of these positions, shown in broken lines, correspond to the respective levels of the four toothed wheels and the fifth, shown in full lines, is a rest or netural position.

The radial disposition of the cam 18 is such that its active part 21 may, upon passage past the toothed wheels, impart to a toothed wheel at the same level a rotation which corresponds to an angular displacement of half a pitch or one pitch, according to the initial position of the teeth of this wheel, and thus cause a corresponding rotation of the drum 1 by one or two steps of the selection blades 2.

Rotation of the drum 1 will take place in one direction or in the other direction according to whether the action of the cam 18 is exerted on a toothed wheel of the upper or lower pair.

By an appropriate selection of the level of the cam 18, it is thus possible to obtain, at will, and for each passage of the cam, as will be described further on with reference to FIGS. 7 and 8, a rotation of the selector drum 1 corresponding to one or two steps of the selector members of the drum in a selected direction.

By spacing apart the two pairs of toothed wheels 13, 14 and 15, 16, as shown in FIG. 1, by an amount greater than the thickness of the active part 21 of the cam 18, this control by means of a single cam enables elimination of the risks of jamming of components of the mechanism during operation.

Downstream of the active part 21, in relation to its direction of motion, the cam 18 has a bearing surface 24, somewhat inset in relation to the peak of the active part 21, adapted to limit the angular displacement of the controlled toothed wheel. As shown in FIG. 4, one of the toothed wheels has just completed its rotation by a fraction of a turn. The peak 22 of the controlled tooth has reached its escape position, whilst the peak 23 of the following tooth comes to abut against the bearing surface 24 which prevents further movement of the toothed wheel by inertia.

In the embodiment shown in FIGS. 5 and 6, the selector drum 36 and the assembly of control elements associated therewith are carried by a support 25 which is able to slide radially, in known manner, between two lateral slideways 26, 27 fixed on a stationary plate 28.

The mechanism also comprises two pairs of axially spaced apart toothed wheels 29, 30 and 31, 32 having the same characteristics as in the preceding example, to which are respectively associated a control pinion 33 and a chainwheel 34 each able to freely turn on a common shaft 35. The step-by-step rotational drive of the drum 36, which carries selection blades 37, takes place through a unitary driving assembly turnably mounted on a shaft 38, said assembly including a pinion 39 meshing with the control pinion 33 and a chainwheel 40 drivably connected to a chainwheel 34 by a chain 41. The drum 36 has a single drive pinion 42 which meshes with the intermediary pinion 39, the assembly of drum 36 and pinion 42 being freely rotatably mounted on a shaft 43.

As in the preceding example, the control of the toothed wheels takes place by means of a cam 44 mounted on and rotatable with a rotary crown 45 selectively axially movable between four discrete active positions as well as a rest or netural position.

According to whether the cam 44 acts on the upper or lower pair of toothed wheels, the drum 36 is caused to rotate in one direction or the other, by one step or by two steps of the selector members, depending upon the initial angular position of the wheel acted upon.

This arrangement of the selector drum 36 and its control members on a single movable support enables the assembly of the patterning device to be out of action without a risk of deregulating the mechanism.

The means for holding the support 25 stationary, the mode of securing the selection levers (in the case where they are also carried by the movable support), as well as the means for axially withdrawing the selector drum to enable it to be replaced or for a modification of its possibilities of selection, have no direct connection with the invention and have not been shown.

FIGS. 7 and 8 show a device for controlling movement of the cam 18 (FIGS. 1 to 3) or 44 (FIGS. 5 and 6) between its various discrete positions.

In this example, a cam 18a has an active part 21a and is slidably mounted in a vertical slideway of a support 19a, integral with the rotary crown 20 of the circular knitting machine. This cam 180 has on its bearing face 46 five superimposed V-shaped notches 47a to 47c. A ball 48 outwardly urged by a spring 49 housed in a recess in the support 19a can bear against the flanks of any of notches 47a to 47s in a manner to define the five discrete positions of the cam 18a. The lower part of. cam 18a is additionally provided with a cylindrical control pin 50.

Between the patterning devices at the periphery of the knitting machine, the stationary plate 6 carries a support bracket 51 on which a cam 52 is pivotally mounted about a shaft 53, which cam 52 comprises two active ramp surfaces 54, 55 which converge to form a passage therebetween. This cam 52 is arranged such that whatever be the heightwise position of the slidable cam 18a, the control pin 50 engages, upon passage, be-

tween the two converging ramp surfaces 54, 55.

The angular disposition of the pivotable cam 52 is determined as a function of data of the pattern to be reproduced by means of a control device, such as a counter, acting on a pin 56 provided on the cam 52.

According to the angular disposition of the cam 52, the pin 56 may be acted upon, during passage, by either of the ramp surfaces 54, 55 to place cam 18a in one of its five discrete positions. Active part 21a then acts on the corresponding toothed wheel associated with each selector drum of the knitting machine.

What is claimed is:

l. A mechanismfor the control of reversible step-bystep rotation of selector drums of patterning devices for the control of knitting components of a circular knitting machine, which drums each have on their pperiphery a series of equidistant selection members, a control device being associated with each drum, said control device comprising first and second pairs of axially spaced apart toothed wheels;

said first pair of toothed wheels being operatively associated with said drum for controlling rotation thereof in a first direction;

said second pair of toothed wheels being operatively associated with said drum for controlling rotation thereof in a second direction opposite to said first direction;

the two toothed wheels of each of said pairs having the same number of teeth;

the two toothed wheels of each of said pairs being rigidly fixed together coaxially with the teeth of one wheel angularly dephased by half a pitch with respect to the other wheel;

a single control member mounted on a movable part of said machine;

means for selectively displacing said single control member to any one of four positions corresponding to the four axial locations of said toothed wheels;

said single control member engageable with a selected one of said toothed wheels dependent upon the position of said single control member, upon movement of said single control member by said movable part, to rotatablydisplace the said pair "corresponding to said selected toothed wheel either by a half pitch or a full pitch of the teeth thereof, dependent upon the angular position of the teeth of said selected toothed wheel, and to thereby rotatably displace said drum by one or two steps of said selection members thereof in one of said directions.

2. A mechanism as claimed in claim 1, wherein said first and second pairs of toothed wheels are adapted to be rotatably displaced in the same direction by said single control member, and further comprising first intermediary transmission means for driving said drum in said first direction for a displacement of one of said pairs of toothed wheels; and second intermediary transmission means for driving said drum in said second direction for a displacement of the other of said pair of toothed wheels.

3. A mechanism as claimed in claim 2, wherein said first intermediary transmission means comprises a first pinion meshing with a second pinion integral with said one of the pairs of toothed wheels; and said second intermediary transmission means comprises a first chainwheel and a chain in driving relationship with a second chainwheel integral with said other pair of toothed wheels.

4. A mechanism as claimed in claim 3, wherein said second pinion and second chainwheel of said intermediary transmission means are integral with the respective pairs of toothed wheels.

5. A mechanism as claimed in claim 2, wherein said two pairs of toothed wheels are disposed coaxially.

6. A mechanism as claimed in claim 2, wherein said selector drum and the assembly of transmission means associated therewith are mounted on a movable support.

7. A mechanism as claimed in claim 1, wherein said single control member is mounted on a rotary crown of said knitting machine; and said single control member comprising an active part engageable with said toothed wheels and downstream of said active part in relation to its direction of motion a bearing surface limiting the angular displacement of the toothed wheel displaced by said active part.

8. A mechanism for the control of reversible step-bystep rotation of selector drums of patterning devices for the control of knitting components of circular knitting machines, which drums each have on their periphery a series of equidistant selection members, said mechanism comprising a control device associated with each drum and including:

first and second pairs of axially spaced apart toothed wheels; each of said toothed wheels of each of said pairs having a peripheral portion, the tangents of said peripheral parts of each of said toothed wheels lying in substantially the same plane; the two toothed wheels of each of said pairs having the same number of teeth; the two toothed wheels of each of said pairs being rigidly fixed together coaxially with the teeth of one wheel angularly dephased by half a pitch with respect to the other wheel; a single control member having an active part and mounted on a movable part of said machine; means for selectively displacing said single control member to any one of four positions corresponding to the four axial locations of said toothed wheels; said control member being relatively movable past the toothed wheels along a direction substantially tangential to said peripheral parts such that said active part contacts a tooth of the peripheral part of a selected one of said toothed wheels to rotatably displace the corresponding pair of toothed wheels either by half a pitch or by a full pitch of the teeth thereof, dependent upon the initial angular position of said selected toothed wheel; means for transmitting rotation of one pair of toothed wheels into rotation of said drum by one step of the selection members thereof in a first direction per half pitch displacement of said one pair of toothed wheels; and means for transmitting rotation of the other pair of toothed wheels into rotation of said drum by one toothed wheels. having the same diameter. 

1. A mechanism for the control of reversible step-by-step rotation of selector drums of patterning devices for the control of knitting components of a circular knitting machine, which drums each have on their pperiphery a series of equidistant selection members, a control device being associated with each drum, said control device comprising first and second pairs of axially spaced apart toothed wheels; said first pair of toothed wheels being operatively associated with said drum for controlling rotation thereof in a first direction; said second pair of toothed wheels being operatively associated with said drum for controlling rotation thereof in a second direction opposite to said first direction; the two toothed wheels of each of said pairs having the same number of teeth; the two Toothed wheels of each of said pairs being rigidly fixed together coaxially with the teeth of one wheel angularly dephased by half a pitch with respect to the other wheel; a single control member mounted on a movable part of said machine; means for selectively displacing said single control member to any one of four positions corresponding to the four axial locations of said toothed wheels; said single control member engageable with a selected one of said toothed wheels dependent upon the position of said single control member, upon movement of said single control member by said movable part, to rotatably displace the said pair corresponding to said selected toothed wheel either by a half pitch or a full pitch of the teeth thereof, dependent upon the angular position of the teeth of said selected toothed wheel, and to thereby rotatably displace said drum by one or two steps of said selection members thereof in one of said directions.
 2. A mechanism as claimed in claim 1, wherein said first and second pairs of toothed wheels are adapted to be rotatably displaced in the same direction by said single control member, and further comprising first intermediary transmission means for driving said drum in said first direction for a displacement of one of said pairs of toothed wheels; and second intermediary transmission means for driving said drum in said second direction for a displacement of the other of said pair of toothed wheels.
 3. A mechanism as claimed in claim 2, wherein said first intermediary transmission means comprises a first pinion meshing with a second pinion integral with said one of the pairs of toothed wheels; and said second intermediary transmission means comprises a first chainwheel and a chain in driving relationship with a second chainwheel integral with said other pair of toothed wheels.
 4. A mechanism as claimed in claim 3, wherein said second pinion and second chainwheel of said intermediary transmission means are integral with the respective pairs of toothed wheels.
 5. A mechanism as claimed in claim 2, wherein said two pairs of toothed wheels are disposed coaxially.
 6. A mechanism as claimed in claim 2, wherein said selector drum and the assembly of transmission means associated therewith are mounted on a movable support.
 7. A mechanism as claimed in claim 1, wherein said single control member is mounted on a rotary crown of said knitting machine; and said single control member comprising an active part engageable with said toothed wheels and downstream of said active part in relation to its direction of motion a bearing surface limiting the angular displacement of the toothed wheel displaced by said active part.
 8. A mechanism for the control of reversible step-by-step rotation of selector drums of patterning devices for the control of knitting components of circular knitting machines, which drums each have on their periphery a series of equidistant selection members, said mechanism comprising a control device associated with each drum and including: first and second pairs of axially spaced apart toothed wheels; each of said toothed wheels of each of said pairs having a peripheral portion, the tangents of said peripheral parts of each of said toothed wheels lying in substantially the same plane; the two toothed wheels of each of said pairs having the same number of teeth; the two toothed wheels of each of said pairs being rigidly fixed together coaxially with the teeth of one wheel angularly dephased by half a pitch with respect to the other wheel; a single control member having an active part and mounted on a movable part of said machine; means for selectively displacing said single control member to any one of four positions corresponding to the four axial locations of said toothed wheels; said control member being relatively movable past the toothed wheels along a direction substantially tangential to said peripheral parts such that said active part contacts a tooth of the peripheRal part of a selected one of said toothed wheels to rotatably displace the corresponding pair of toothed wheels either by half a pitch or by a full pitch of the teeth thereof, dependent upon the initial angular position of said selected toothed wheel; means for transmitting rotation of one pair of toothed wheels into rotation of said drum by one step of the selection members thereof in a first direction per half pitch displacement of said one pair of toothed wheels; and means for transmitting rotation of the other pair of toothed wheels into rotation of said drum by one step of the selection members thereof in a second direction opposite to said first direction per half pitch displacement of said other pair of toothed wheels.
 9. A mechanism as claimed in claim 8, wherein said first and second pairs of toothed wheels are independently coaxially mounted on a common shaft, all of said toothed wheels having the same diameter. 